Fifty Shades of Grey author E L James experienced a frightening 18-hour bout of amnesia two years ago, Yahoo! Entertainment reports.

The writer revealed the incident in an interview for the podcast White Wine Question Time, hosted by British journalist Kate Thornton.

“I think it was September [or] October 2019 and I was in Cornwall and I just suddenly started feeling odd,” James said. “I phoned my husband who was walking our dogs, and he came back and he found me sat in our little study that I have in our house in Cornwall, and I couldn’t remember where I was.”

She was diagnosed with transient global amnesia, a health condition that can be caused by emotional distress. James said she’d been experiencing panic attacks that she attributes to the success of her books and their accompanying movies.

“I think it’s mainly to do with the negative sides of all of this,” she said. “I didn’t have a good time making the first movie. I shudder thinking about it.”

Transient global amnesia can be caused by other factors as well, but James dismissed the possibility of at least one of them.

“I think it was probably stress related,” James told Thornton. “You can get it if you step into very, very cold water, [or] if you’ve had incredibly rigorous sex. Sadly, that wasn’t the cause.”

James’ most recent book, Freed, was published last month.

Michael Schaub is a Texas-based journalist and regular contributor to NPR.